Viking 10-Piece #58510 BR-10 Bolt Extractor and Pilot Drill Set. Features 5 sizes of type 420-UB Spiral Style Hi-Carbon steel Bolt, Screw and Pipe extractors, also called EZ Outs. Ideal for removing broken screws, bolts, threaded parts, and pipes, this set is capable of removing fasteners from 3/32" to 5/8" diameter and pipe sizes up to 1/4" NPT. Broken piece is extracted without damage to the threads. Includes matching type 240-AL 135° split point left-hand spiral pilot drill bits. Set includes Extractor sizes #1, #2, #3, #4, #5, Left-hand pilot bit sizes 3/32", 1/8", 3/16", 1/4", 5/16" and a metal index storage case.
TO USE: Drill pilot hole in the center of broken stud using the included left-hand spiral drill bit. Insert extractor tip into drilled hole and then turn counter-clockwise using a wrench on end of extractor. Use of a penetrant or lubricant is highly recommended while drilling and removing the broken fastener. Occasionally the use of a left-hand pilot bit will remove the fastener without the need to use the extractor. It is not advisable to use a standard right hand twist drill bit as this may further tighten the fastener into the hole and make removal more difficult.